Knob and spindle mechanism for door latches



Jan. 2, 1940. J. MILLER vKNOB AND SPINDLE MEGHANISM FOR DOOR LATGHESFiled July 7, 1938:

INVENTOR Uu ATTORNEY Patented Jan. 2, 1940 KNOB AND SPINDLE MECHANISMLATCHES Julius Miller,

Fon Doon Application July 7, 1938, SerialNo. 217,862

1 Claim.

This invention relates to knob and spindle mechanism for door latches ofthe type in which a spring-projected latch bolt automatically engages alatch plate on a door jamb adjacent thev l `rendered valternatelyoperative and inoperative by manipulation of the spindle, suchmanipulation being normally possible the door. y

Aiurther object of the invention is to provide a door knob and platecombined as a unit whereby the knob cannot be removed from the spindlewithout removing the plate from the door, in combination with meansfor'securing the plate to the-door, which means is invisible at theoutside of the door when the plate is in position thereon.

Other objects and advantages of the invention will appear as thedescription proceeds.

In the accompanying drawing,

Fig. 1 is a longitudinal sectional view of a knob and spindle mechanismconstructed in accordance with the present invention, attached to aportion of a door, both knobs being shown in operative engagement withthe spindle;

Fig. 2 is a View similar to Fig. 1, but showing the spindle out ofoperative engagement with one of the knobs; i

Fig. 3 is an end view of the knob shown at the left in Fig. 2, said knobbeing detached from its door plate; and

Fig. 4 is a perspective view of the spindle assembly with thepermanentlyv operative knob attached thereto. l

Referring to the drawing, I designates a portion of a door which may beassumed to be hinged at one edge to the door frame and at its oppositeedge provided with an automatically acting spring latch, the latch boltof which (not shown) is actuated by a cam follower 2, through whichpasses a spindle 3 oi generally square shape in cross-section, wherebyrotary motion of the spindle will serve to rotate the cam 2 thereby toonly at one side of retract the latch against the tension of its spring.f

At oneend of the spindle a knob 4 is secured thereto in the usualmanner, name1y,the corners (Cl. l0-149) of the square-spindle 'arethreaded for engagement with an interiorly vthreadedbore in the shank ofthe knob t therebyto permit adjustment of the operative length of thespindle l:for

use with doors of different'thicknesses, the usual set screw 5 passingradially through the shank of the knob into engagement with one of theat sides of the spindle for maintaining the knob in its adjustedposition on the spindle. The shank of the knob Il is provided at the endthereof adjacent the door with a cylindrical portion 4@ of smallerdiameter than the rest oi the shank,

said portion being adapted to pass freely through a central opening-inadoor plate 6. .The said portion la has formed therein an annular groovein which is mounted a split ring l' preferably made of spring wire ofround cross section.

' At the opposite or outer side of thedoor, a

plate 8 is provided in which is mounted for free rotation'the shank of aknob 9, the end of the Aknob shank beingv flanged over at the inner sideof the plate to prevent separation of the knob and plate, so that thesetwo members constitute a unit.l The plate Bis 'preferably provided atits inner side with a plurality of interiorly threaded Uli sleeves l0seated in bores extending through the wood o the door,y each of saidsleeves being engaged by a screw Il extending through the plate 6 atvthe other side of the door. .This arrangement makes it .impossible-toyremove the knobcarrying plate 8, or tolocate the screws holding saidplate,"ex cept from the inside. The knob 9 is provided with an openingl2 therethrough, said opening being squaref'or the ygreater portion ofvits length, while the spindle 3v is provided at the end thereof with acylindrical portion 3a, immediately adjacent to the square portion.

Secured on the spindle, and dispose'd'within an opening iormed'in thedoor, is a stop washer I4, which may either be threaded on to thespindle or merely provided.- with a square opening for the passage ofthe spindle therethrough, and in either case a set screw l5 passesradially through the washer and impinges on the spindle, therebymaintaining the washer at a fixed posif tion. As will be -noted in Figs.l, 2 and 4, the

washer is secured on the spindle at such a p oint portion 3b into andout of engagement with the l square opening I2 of the knob 9.

From the foregoing it will be obvious that the knob 4 is at all timessecured to the spindle so that the latter will turn with-the knob andthus impart rotary motion to the cam follower 2 thereby to retract thelatch bolt whenever the knob ll is turned. With the spindle in theposition shown in Fig. 1, the knob 9 is also operative to turn thespindle because the square portion 3b of the latter is within the squareopening I2 oi the knob. However, assuming that the knob 9 is at theouter side of the door and it is desired to prevent operation of thelatch bolt from that side, this is accomplished by exerting a slightpull on the inside knob 4 to withdraw the square portion 3b from itssquare seat in the knob 9, as shown in Fig. 2, in which position theknob 9 may be freely rotated around the cylindrical portion 3a of thespindle but is entirely ineilective to rotate the spindle. Thelongitudinal move- `ments of the spindle in opposite directions arelimited by the abutment or" the washer i4 against the cam follower 2 onone side and against the shank knob 9 and its plate 3 on the other side.The split ring 'I in its expanded condition is of ySlightly largerdiameter than the opening in the plate 6 so that when the spindle is inengagement with knob 9 the ring abutsl against the inner side of plate 5and offers sufficient resistance to the movement of the spindle toprevent accidental disengagement from said knob Sl. On the other hand,owing to the cylindrical form of the stock from which the ring is made.a pull on the knob l causes the ring to contract sufficiently to enterthe plate opening as. shown in Fig. 2, the movement of the spindle beingstopped by abutment el the washer Ill against the latch follower 2before the ring passes completely out of the plate opening.

It will thus be readily seen that, with the parts in the position shownin Fig. l, the latch bolt may be operated by turning either knob, but inthe position shown in Fig. 2, only the knob 4 is effective to rotate thespindle and thereby withdraw the latch bolt, and that the spindle can bereplaced in operative engagement with knob 9 only by pushing on the knobl and, if necessary, turing the latter slightly to carry the square endof the spindle into register with the opening I2 in the shank of knob 9.However, means is provided whereby a person who has accidentally lockedhimself out by closing the door after him with the parts in the positionshown in Fig. 2, may operate the spindle to withdraw the latch bolt. Inthe example shown in the drawing, the knob 9 is provided with a bore I5in axial alinement with the square opening I2 and with .the cylindricalportion 3'au of the spindle which is provided at its end with aninteriorly threaded bore or socket I6 for engagement with the threadedend of a key Il', whereby one iinding himself locked out may thread thekey into the socket and pull the spindle into operative engagement withknob 9, or by rotating the key until it will go no further withoutturning the spindle and thus withdrawing the latch bolt. While a screwengagement between the spindle and key is shown herein, it will bereadily seen that some other form of connection, such for instance as aslot and pin, may be devised to make it dicult for unauthorized personsto operate the spindle from outside the door without having theimplement designed for that purpose.

Having thus described my invention, what I claim is: v

In a door latch having an automatically projected latch bolt androckable means for retracting the same, an actuating spindle in slidableengagement with said retracting means and op erative to a-ctuate thesame in all positions of the spindle, a knob secured to the spindle atone end thereof for manually rocking and sliding the spindle, a washersecured to said spindle for limiting the sliding movement of the spindlein opposite directions, a second knob mounted for free rotation inalignment with the opposite end of the spindle and provided with anopening for the reception of a portion of the spindle, said opening andspindle portion being of cooperating form in cross-section whereby whenthe spindle is slid in one direction it will be operatively engaged bysaid knob and when slid in the opposite direction the knob willbe freeto rotate Without eect on the spindle, a door plate having an opening inwhich a shank portion of said rst knob is mounted for rotation andsliding movement, said shank portion having a circumferential groovetherein, and a split ring of resilient material mounted in said grooveand presenting flexible resistance to sliding movement of the shankportion of the knob in said door plate. v

JULIUS MILLER.

